One problem with LED illumination of large areas with a large amount of light is to manage the heat from the LED devices, and in particular, to prevent the large temperature rise associated with locating a large number of LED devices in a small area, to efficiently power the devices from a low-cost power supply, and to provide a low-cost substrate on which to mount the LED devices.
Architectural lighting often needs different spectra of light and different amounts of light for different times of the day.
The conventional approach for home growers of plants is to select lighting depending on the types and quantity of plants they grow. As a general rule, inexpensive lights tend to be the most expensive to operate and least effective in promoting plant growth. Home growers typically choose fluorescent to grow herbs and to germinate flowering varieties. High-pressure sodium (HPS) lights or metal halide (MH) lights are often chosen for commercial-scale indoor growing of plants, but these high-wattage systems create excessive heat and consume excessive energy. All of these sources generate much heat and much of their light is in wavelengths that are not efficiently used by plants.
Some light-emitting-diode (LED) grow lights maximize blue and red light to provide a balance for plants, but high initial purchase cost has prohibited mass adoption for home growers. In addition, even conventional LED grow lights are driven with high current, often consuming 100 to 300 watts of electrical power, which leads to excess heat, forcing growers to keep the LEDs 18 to 30 or more inches away from the plants (which uses up valuable volumetric indoor space) and to use fans and air conditioning (involving further cost and volumetric space) in order to remove harmful excess heat.
U.S. Pat. No. 8,471,274 to Golle, et al. issued on Jun. 25, 2013 with the title “LED light disposed on a flexible substrate and connected with a printed 3D conductor,” and is incorporated herein by reference. U.S. Pat. No. 8,471,274 describes a flexible planar substrate including a first surface that is planar, at least one bare light-emitting-diode (“LED”) die coupled to the substrate and conductive ink electrically coupling the at least one bare LED die, wherein the conductive ink is disposed on the substrate and extends onto a surface of the LED that is out-of-plane from the first surface.
U.S. Pat. No. 7,607,815 to Pang issued on Oct. 27, 2009 with the title “Low profile and high efficiency lighting device for backlighting applications” and is incorporated herein by reference. U.S. Pat. No. 7,607,815 describes a light source having a flexible substrate and a plurality of dies having LEDs is disclosed. The light source can be conveniently utilized to provide an extended light source by bonding the light source to a suitable light pipe. The substrate is divided into first and second regions. The dies are bonded to the substrate in a first region. A portion of the surface of the substrate in the second region is reflective. The substrate is bent such that the second region forms a reflector that reflects light that would otherwise be emitted in a non-useful direction to a more useful direction. The substrate can be constructed from a three-layer flexible circuit carrier in which the dies are mounted on a bottom metal layer to provide an improved thermal path for heat generated in the dies.
U.S. Pat. No. 7,617,857 to Froese issued Nov. 17, 2009 with the title “Illuminated window blind assembly” and is incorporated herein by reference. U.S. Pat. No. 77,617,857 describes an illuminated blind assembly having either horizontally oriented slats or vertically oriented slats. The slats have structure that allows them to be illuminated. The slats can be A.C. or D.C. powered. The window blind assembly may have a housing containing rechargeable batteries. These batteries can be charged by photovoltaic solar cells that are positioned on the top surfaces of the slats. The window blind assembly can have a tilt/raise/lower pulley system structure and electrical servos in a housing extending across the top of the window blind assembly. An infrared remote sensor can be located in the front of the housing for controlling the electric servos and the switch for lighting up the slats.
U.S. Pat. No. 9,116,276 to Montfort et al. issued on Aug. 25, 2015 with the title “Room divider with illuminated light guide blind blade” and is incorporated herein by reference. U.S. Pat. No. 9,116,276 describes an apparatus that includes a first holder configured to hold a light source and having an interface for receiving power to feed to said light source, and a light guide plate configured to be coupled to said first holder and guide light emitted by the light source out from at least one surface of the light guide plate.
What is needed is a more efficient and effective lighting solutions that are useful for architectural lighting as well as for growing plants, particularly in large mass-production warehouse indoor growing facilities.